Traditionally, automobiles are driven by an internal combustion engine (ICE) that produces drive torque. The drive torque is transferred through a powertrain to drive wheels. The powertrain includes a transmission that transfers drive torque through a gear reduction. The desired drive torque is regulated by a driver input, such as an accelerator pedal or a cruise control system. A particular drive characteristic (i.e., acceleration or feel) is associated with the desired drive torque.
Torque-based control can be implemented to achieve the desired drive characteristic. Using an axle torque-based control, the accelerator pedal position is interpreted as a desired axle torque. The engine and transmission are controlled to deliver the desired axle torque to provide the desired drive characteristic. In some applications (e.g., manual transmissions) it is not possible to use an axle torque-based control. An engine torque-based control is used instead. Using the engine torque-based control, the accelerator pedal position is interpreted as an engine torque request and the engine is controlled to deliver the requested engine torque to provide the desired drive characteristic.
Difficulties have arisen in achieving the same drive characteristic whether using the axle torque-based control or the engine torque-based control. In other words, the same drive characteristic or feel achieved using the axle torque-based control is not achieved using the engine torque-based control.